Two metal wires having conductivities σ1 and σ2 respectively have same dimensions. If they are connected in series the effective conductivity of the combination is
(a) σ1+ σ2/2
(b) σ1 - σ2/2
(c) σ1+ σ2/σ1σ2
(d) 2σ1σ2/σ1+ σ2
Correct option (d) 2σ1σ2/σ + σ1 + σ + σ2
Explanation:
